Rahonavis (was Re: Ornithoms, Parrots, and others)

["Thomas R. Holtz, Jr." <th81@umail.umd.edu>]

At 03:14 PM 11/12/98 EST, Dinogeorge wrote:

>I do believe we have a volant deinonychosaurian in the fossil record of
>Madagascar: _Rahonavis_. The problem is to establish that it is on the other
>side of the phylogenetic bracket, which is difficult because (1) the remains
>are incomplete and (2) it underwent a lot of evolution itself since diverging
>from the common ancestor of deinonychosaurians and birds.

I suspected that _Rahonavis_ would fall out as a deinonychosaur in my latest
phylogeny, but in my latest runs it comes out as a basal avialian (closer to
birds than to dromaeosaurs).  However, as it is so fragmentary, and as the
newer specimens of dromaeosaurids from both the Cloverly and Mongolia are
showing a wider ranger of morphologies within that taxon, I wouldn't be
terribly surprised if it didn't make the hop over to the dromaeo-side of things.

Thomas R. Holtz, Jr.
Vertebrate Paleontologist     Webpage: http://www.geol.umd.edu
Dept. of Geology              Email:tholtz@geol.umd.edu
University of Maryland        Phone:301-405-4084
College Park, MD  20742       Fax:  301-314-9661